Aluminum is a material that is excellent in conductivity and corrosion resistance and is lightweight. In battery application, for example, as the positive electrode of a nonaqueous-electrolyte battery such as a lithium-ion battery, an aluminum foil is used by applying on its surface an active material such as lithium cobalt oxide. More specifically, a paste-like material formed by mixing a conductive aid, binder resin, and the like with a powder of active material such as lithium cobalt oxide is applied onto both surfaces of an aluminum foil and then dried to produce a positive electrode (Patent Literature 1).
On the other hand, a metallic porous body having a three-dimensional network structure is used in applications such as various filters and battery electrode. For example, CELMET (Registered trademark of Sumitomo Electric Industries, Ltd.) made of nickel is used as an electrode material of batteries such as a nickel-hydrogen battery and a nickel-cadmium battery. When such a metallic porous body is used as an electrode, the metallic porous body is filled with a paste-like material formed by mixing a conductive aid, binder resin, and the like with an active material to produce the electrode. For example, Patent Literature 2 describes an alkaline battery's electrode formed by filling a collector formed of a metallic porous body with an active material.